Acute In Vivo Multielectrode Recordings from the Mouse Suprachiasmatic Nucleus.

The discovery of the suprachiasmatic nucleus (SCN) as the master mammalian pacemaker has since opened up a variety of alternative methods for assessing how external timing cues influence the clock. One powerful approach for understanding how sensory inputs influence the SCN is to monitor acute changes in SCN electrophysiological activity via in vivo extracellular recording. This methodology offers the ability to monitor stimulus-evoked changes in SCN function at very fine timescales and to rapidly test multiple stimuli and/or stimulus repeats within a single animal. In this chapter we describe our methods for acute in vivo multielectrode recording in head-fixed, anesthetized rodents. These allow for monitoring of single-cell/population activity for >12 h; enable the delivery of carefully controlled sensory stimuli; can be used alongside an array of established or novel experimental tools; and are easily adapted to study activity in any other brain region.